List of awsome UI:s

I'm a big fan of UIs and like to try out many of them. I've gathered most of them to supply all you guys.
But I will need your help as well. Please fill in the thread with some nice UIs and their download link and I'll update as fast as I can.

What makes a good UI is to borrow a quote is in the eye of the beholder.
What makes a UI suitable for one person is not always the same as another.
The threads are there for inspiration, and in many cases constructive criticism where people are looking for improvement.
A premade UI is a quick fix, and teaches you only so much about improving your own.

Rant aside, a list of perhaps the well supported ones is not a bad idea for people who need something functional in a hurry but should be a start, not the end.

All but two really got what was meant by the original post, but since there still seems to be confusion I will try to clarify again.
There is a Post your UI thread already, which is meant for either your own custom UI's, or edit's of other existing ones.
This one started with a request for ones which are downloadable and usable with minimal effort.
I then narrowed that selection with the requests for something actively supported whether that be by a community in the case of TukUI etc, or by the author as is iLive.

We are not telling you that a UI is awesome or not, since anyone posting the links as I have described are offering their own opinion.
That is up to you to decide on your preference.

TukUI v11 is out! TukUI is by far the most amazing UI there is. You can customize it in almost every way you need and it's pixel perfect and clean. It works on any screen resolution and the TukUI community is very helpful in assisting you with any questions. They even make pre-made packages and extra mods specifically for TukUI. I've been a long time user and never looked back. Go Tukz!

TukUI v11 is out! TukUI is by far the most amazing UI there is. You can customize it in almost every way you need and it's pixel perfect and clean. It works on any screen resolution and the TukUI community is very helpful in assisting you with any questions. They even make pre-made packages and extra mods specifically for TukUI. I've been a long time user and never looked back. Go Tukz!

Since you're grouping them in a bit more of an organized, I'd like to see an addendum made for NiconazeUI. Its main function is a Ret Paladin UI(even comes with ret-specific macros and a pre-configured ICD-tracking Clcret). It looks like he uses it for his warlock as well, but it's primarily a ret UI. Your choice in the matter though, because it's not listed under class-specific UI's on Wowinterface.

the Damia UI link is broken. I think it says the profile has been deleted. It shows some error then quickly redirects to http://www.wowinterface.com/addons.php. So I'm guessing its not supported anymore.